diff --git a/app/models/site.rb b/app/models/site.rb
index c46c666e0b4..1390c1c25a3 100644
--- a/app/models/site.rb
+++ b/app/models/site.rb
@@ -109,7 +109,16 @@ class Site
     if @guardian.can_lazy_load_categories?
       preloaded_category_ids = []
       if @guardian.authenticated?
-        preloaded_category_ids.concat(@guardian.user.secured_sidebar_category_ids(@guardian))
+        sidebar_category_ids = @guardian.user.secured_sidebar_category_ids(@guardian)
+        preloaded_category_ids.concat(
+          Category
+            .secured(@guardian)
+            .select(:parent_category_id)
+            .distinct
+            .where(id: sidebar_category_ids)
+            .pluck(:parent_category_id),
+        )
+        preloaded_category_ids.concat(sidebar_category_ids)
       end
     end
 
diff --git a/spec/models/site_spec.rb b/spec/models/site_spec.rb
index ff49ad5c5c9..cc23095c014 100644
--- a/spec/models/site_spec.rb
+++ b/spec/models/site_spec.rb
@@ -183,6 +183,40 @@ RSpec.describe Site do
         DiscoursePluginRegistry.clear_modifiers!
       end
     end
+
+    context "with lazy loaded categories enabled" do
+      fab!(:user)
+
+      before { SiteSetting.lazy_load_categories_groups = "#{Group::AUTO_GROUPS[:everyone]}" }
+
+      it "does not return any categories for anonymous users" do
+        site = Site.new(Guardian.new)
+
+        expect(site.categories).to eq([])
+      end
+
+      it "returns only sidebar categories and their parent categories" do
+        parent_category = Fabricate(:category)
+        category.update!(parent_category: parent_category)
+        Fabricate(:category_sidebar_section_link, linkable: category, user: user)
+
+        site = Site.new(Guardian.new(user))
+
+        expect(site.categories.map { |c| c[:id] }).to contain_exactly(
+          parent_category.id,
+          category.id,
+        )
+      end
+
+      it "returns only visible sidebar categories" do
+        Fabricate(:category_sidebar_section_link, linkable: category, user: user)
+        category.update!(read_restricted: true)
+
+        site = Site.new(Guardian.new(user))
+
+        expect(site.categories).to eq([])
+      end
+    end
   end
 
   it "omits groups user can not see" do
diff --git a/spec/serializers/site_serializer_spec.rb b/spec/serializers/site_serializer_spec.rb
index 38019a3a6e8..668c30f3894 100644
--- a/spec/serializers/site_serializer_spec.rb
+++ b/spec/serializers/site_serializer_spec.rb
@@ -133,32 +133,24 @@ RSpec.describe SiteSerializer do
 
   context "with lazy loaded categories enabled" do
     fab!(:user)
-    let(:guardian) { Guardian.new(user) }
+    fab!(:category)
+    fab!(:sidebar) { Fabricate(:category_sidebar_section_link, linkable: category, user: user) }
 
     before { SiteSetting.lazy_load_categories_groups = "#{Group::AUTO_GROUPS[:everyone]}" }
 
-    it "categories does not include any categories for anonymous users" do
+    it "does not include any categories for anonymous users" do
       serialized = described_class.new(Site.new(guardian), scope: guardian, root: false).as_json
 
       expect(serialized[:categories]).to eq(nil)
     end
 
-    it "categories include only sidebar categories" do
-      Fabricate(:category_sidebar_section_link, linkable: category, user: user)
+    it "includes preloaded categories for logged in users" do
+      guardian = Guardian.new(user)
 
       serialized = described_class.new(Site.new(guardian), scope: guardian, root: false).as_json
 
       expect(serialized[:categories].map { |c| c[:id] }).to contain_exactly(category.id)
     end
-
-    it "categories include only visible sidebar categories" do
-      Fabricate(:category_sidebar_section_link, linkable: category, user: user)
-      category.update!(read_restricted: true)
-
-      serialized = described_class.new(Site.new(guardian), scope: guardian, root: false).as_json
-
-      expect(serialized[:categories]).to eq(nil)
-    end
   end
 
   describe "#anonymous_default_navigation_menu_tags" do